DESCRIPTION (adapted from the application) Recent clinic-based studies strongly suggest a marked increase in the incidence of type 2 diabetes in adolescents. However, population or community-based studies have not as yet been performed to document the epidemiology of type 2 diabetes in adolescents and the natural history of this disease. This application provides a unique opportunity to address these issues in a large (4,373 student), well-defined (47% female, 53% male), racially integrated (46.7% African-American, 47.7% non-Hispanic white) school district containing a wide range of socio-economic statuses. Since, 1973 a member of the research team has performed community-based studies of lipids and cardiovascular risk factors on students and their families in this district. This 4-year study will use a cohort design to define the epidemiology and risk factors for the development and progression to type 2 diabetes. The specific aims of the study are: 1) to determine the prevalence of insulin resistance, carbohydrate intolerance, and diagnosed and undiagnosed diabetes and risk factors associated with type 2 diabetes in a cohort of adolescents in grades 5 through 12; and 2) to determine each-year the progression to insulin resistance, carbohydrate intolerance and diabetes in a cohort of adolescents over a 4 year interval. To accomplish these goals information concerning personal medical and family history of diabetes, physical examination (body mass index, stage of puberty, acanthosis nigricans, waist circumference) and fasting and 2-hour post glucose load plasma glucose and insulin concentration will be collected, measured and analyzed each year of the study. This application will provide unique, community-based information that will: 1) define the prevalence of insulin resistance, carbohydrate intolerance, and diagnosed and undiagnosed type 2 diabetes in adolescents with an enriched African-American population and 2) identify risk factors and predictors for the development and progression to type 2 diabetes. These data are critical to the development of effective individual and public health intervention strategies to prevent type 2 diabetes and its complications in adolescence.